1. Technical Field
The present invention relates to an antenna structure, and more particularly to an antenna structure capable of enhancing the radiation effect of the entire antenna.
2. Related Art
With the development of wireless communication technologies, many wireless communication devices, such as mobile phones, notebook computers, personal digital assistants (PDAs), GPS Satellite Navigation Systems, and E-book readers, have been developed. Aside from wireless communication functions, by replacing a conventional external antenna with an embedded antenna, the wireless communication devices can be built with an attractive, light, and thin industrial design while having a good quality of wireless communication.
However, in order to ensure an attractive design with accompanying sensation of quality, the housing of electric devices is expected to be made of metal, or be plated with a metal layer, influences the quality of wireless communication. Due to the shielding effect of metal, the delivery of electromagnetic waves is blocked, and antenna signal quality suffers.
FIG. 1 is a schematic view of a conventional wireless communication device 1a. Presently, in order to solve the above problem a housing 12a must have a non-metal portion 122a and a metal portion 124a. The non-metal portion 122a is made of a non-metal material such as plastic and carbon fiber, so that electromagnetic waves may be received by an antenna (not shown), in the housing 12a through the non-metal portion 122a, or electromagnetic waves radiated by the antenna may be radiated out through a hole 14a. 
FIG. 2 is a schematic view of US Patent Application Publication No. 20100141535. Please refer to FIG. 2, in which a metal sheet 24a is disposed on a housing 22a of an electronic device 2a to improve the field pattern and the average gain of an antenna 26a in the housing 22a. However, the metal sheet 24a must avoid being overlapped excessively with the antenna 26a, otherwise it is not possible to improve the efficacy of antenna gain, and the shielding effect described above will result.